Synthesis of cyclopentadienyl metal coordination complexes from metal hydrocarbyloxides

ABSTRACT

A process for preparing bridged mono- and bis(cyclopentadienyl) metal dihydrocarbyloxy coordination complexes (I) by contacting in the presence of an aprotic organic diluent a metal compound of the formula M(OR) 4  with a dianionic salt compound. A process for preparing bridged mono- and bis(cyclopentadienyl) dihydrocarbyl metal coordination complexes (II) by contacting a complex (I) with a hydrocarbylation agent. A process for preparing bridged mono- and bis(cyclopentadienyl) metal dihalide coordination complexes (III) by contacting a complex (I) with a halogenation agent.

This is a divisional of application Ser. No. 08/186,402 filed Jan. 25,1994 now U.S. Pat. No. 5,504,223.

BACKGROUND OF THE INVENTION

The present invention relates to a process for preparing certain bridgedmono- and bis-cyclopentadienyl metal dihydrocarbyloxy coordinationcomplexes starting from metal hydrocarbyloxide compounds. The presentinvention also relates to a process for preparing bridged mono- andbis-cyclopentadienyl dihydrocarbyl metal coordination complexes and to aprocess for preparing bridged mono- and bis-cyclopentadienyl metaldihalide coordination complexes both starting from the correspondingbridged mono- or bis-cyclopentadienyl metal dihydrocarbyloxycoordination complexes.

Bridged mono- and bis-cyclopentadienyl metal dihalide coordinationcomplexes and bridged mono- and bis-cyclopentadienyl dihydrocarbyl metalcoordination complexes are known and useful as addition polymerizationcatalysts or as components or precursors thereof.

In "Metallkomplexe mit verbrueckten permethyliertenCyclopentadienylliganden" of P. Jutzi and R. Dickbreder, Chem. Ber. 119,1750-1754 (1986) the synthesis is described ofdimethylsilanediyl-bridged bis(permethylated cyclopentadienyl)titaniumdichlorides from the tetrahydrofuran (THF) adducts of titaniumtetrachloride and the dimethylsilanediyl-bridged bis(permethylatedcyclopentadienyl)dianion derivatives.

In "ansa-Metallocene derivatives: XVII. Racemic and mesodiastereoisomers of group IV metallocene derivatives with symmetricallysubstituted, dimethylsilanediyl-bridged ligand frameworks. Crystalstructure of R,S-Me₂ Si(3-t-Bu-MeCSH₂)₂ ZrCl₂ " of H. Wiesenfeldt etal., Journal of Organometallic Chemistry, 369 (1989) 359-370 thesynthesis is described of dimethylsilanediyl-bridged bis(substitutedcyclopentadienyl)titanium dichloride complexes from the THF-adducts oftitanium trichoride and the dimethylsilanediyl-bridged bis(substitutedcyclopentadienyl)dianion derivatives.

In "Synthesis and Complexation of Linked Cyclopentadienyl-Amido Ligands"of J. Okuda, Chem. Ber. 123 (1990) 1649-1651 the preparation isdescribed of a bridged mono(substituted cyclopentadienyl)titaniumdichloride complex from the THF-adduct of titanium tetrachloride and thedilithium salt of(tert-butylamino)dimethylsilyl!(tert-butyl)cyclopentadienide.

Bridged mono-cyclopentadienyl metal dihalide coordination complexes arealso prepared in U.S. Pat. No. 5,026,798 from titanium tetrachloridecompounds or ether adducts thereof and the dilithium salts of bridgedmonocyclopentadienyl ligand compounds.

Further, EP-A-0,416,815 teaches a process to prepare bridgedmono-cyclopentadienyl metal dihalide coordination complexes startingfrom the transition metal tetrahalide and a Group 1 or Grignardderivative of the bridged mono-cyclopentadienyl ligand compounds.

The above-mentioned synthesis methods to prepare the bridged mono- andbis-cyclopentadienyl metal dihalide coordination complexes use metaltetrahalide compounds as starting materials, which are corrosive, toxic,and air and moisture sensitive. In order to facilitate handling thereof,prior to the reaction step the transition metal tetrahalide compound istypically converted to its ether-adduct in a separate step with forexample THF or diethyl ether. This adduct formation step in itselfproceeds with difficulty, requiring low to very low temperatures, and aninert atmosphere. The adduct is usually recovered before it is reactedwith the dianionic derivative of the ligand compound. The yield of theadduct formation step or steps is less than quantitative. Furthermore,the reaction mixture of the transition metal tetrahalide compound andthe dianionic derivative of the bridged cyclopentadienyl ligand compoundrequires a multi-step, laborious recovery and purification procedure.Typically, after the reaction step, the solvent is removed, the productredissolved by adding dichloromethane or toluene or a mixture thereof,the metal halide byproduct, typically lithium chloride, removed byfiltration of the mixture, the solvent removed at least partially,followed by redissolving the solid product and crystallizing theproduct, optionally followed by one or more further recrystallizationprocedures.

Further, it is known to from EP-A-0,416,815 and EP-A-0,514,828 toprepare bridged mono-cyclopentadienyl metal dihalide coordinationcomplexes, by reacting the THF-adduct of a transition metal trihalidecompound, especially TiCl₃, with the dianionic derivative of thecyclopentadienyl ligand. The resulting complex is contacted with anon-interfering oxidizing agent, such as for example AgCl(EP-A-0,416,815), or with an organic halide to raise the oxidation stateof the metal to form the desired dihalide complex. Apart from requiringan extra reaction step, that is the oxidation step, this process alsostarts from the transition metal trihalide or an ether-adduct thereofwhich has the disadvantages listed above, and requires long reactiontimes to be prepared. Furthermore, the complex resulting from thereaction between the ether adduct of the transition metal trihalidecompound with the dianionic derivative of the cyclopentadienyl ligand,i.e. the cyclopentadienyl metal(III) monohalide coordination complex, isthermally unstable.

The bridged mono-cyclopentadienyl dihydrocarbyl metal coordinationcomplexes can be prepared by hydrocarbylating the corresponding bridgedmono-cyclopentadienyl metal dihalide coordination complexes with aGrignard, lithium, sodium or potassium salt of the hydrocarbyl ligand.This is described, for example, in EP-A-0,418,044, example 3 and WO92/00333. These preparation processes inherently have the disadvantagesassociated with the preparations of the bridged mono-cyclopentadienylmetal dihalide coordination complexes.

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to a process for preparinga metal dihydrocarbyloxy coordination complex corresponding to theformula: ##STR1## wherein: M is titanium;

Cp* is a cyclopentadienyl group bound in an η⁵ bonding mode to M or sucha cyclopentadienyl group substituted with from one to four substituentsselected from the group consisting of hydrocarbyl, silyl, germyl, halo,hydrocarbyloxy, amino, and mixtures thereof, said substituent having upto 20 nonhydrogen atoms, or optionally, two substituents together causeCp* to have a fused ring structure;

Z is a divalent moiety comprising boron, or a member of Group 14 of thePeriodic Table of the Elements, and optionally sulfur or oxygen, saidmoiety having up to 50 non-hydrogen atoms, and optionally Cp* and Ztogether form a fused ring system;

Y is a) a divalent anionic ligand group comprising nitrogen, phosphorus,oxygen or sulfur and having up to 20 non-hydrogen atoms, said Y beingbonded to Z and M through said nitrogen, phosphorus, oxygen or sulfur,and optionally Y and Z together form a fused ring system, or b) acyclopentadienyl group bound in an η⁵ bonding mode to M or such acyclopentadienyl group substituted with from one to four substituentsselected from the group consisting of hydrocarbyl, silyl, germyl, halo,hydrocarbyloxy, amino, and mixtures thereof, said substituent having upto 20 nonhydrogen atoms, or optionally, two substituents together causeY to have a fused ring structure; and

R independently each occurrence is a hydrocarbyl group having from 1 to20 carbon atoms; the steps of the process comprising:

contacting in the presence of an aprotic organic diluent a metalcompound of the formula: M(OR)₄ wherein M and R are as previouslydefined with a dianionic salt compound corresponding to the formula:

    (L.sup.+x).sub.y (Cp*--Z--Y).sup.-2 or ((LX).sup.+x).sub.y (Cp*--Z--Y).sup.-2

wherein:

L is a metal of Group 1 or 2 of the Periodic Table of the Elements,

X independently is chloro, bromo, or iodo,

x and y are either 1 or 2 and the product of x

and y equals 2, and

Cp*, Z, and Y are as previously defined;

to form the complex of formula (I).

In another aspect, the present invention relates to a process forpreparing a metal dihydrocarbyl coordination complex corresponding tothe formula: ##STR2## wherein: M is titanium;

Cp* is a cyclopentadienyl group bound in an η⁵ bonding mode to M or sucha cyclopentadienyl group substituted with from one to four substituentsselected from the group consisting of hydrocarbyl, silyl, germyl, halo,hydrocarbyloxy, amino, and mixtures thereof, said substituent having upto 20 nonhydrogen atoms, or optionally, two substituents together causeCp* to have a fused ring structure;

Z is a divalent moiety comprising boron, or a member of Group 14 of thePeriodic Table of the Elements, and optionally sulfur or oxygen, saidmoiety having up to 50 non-hydrogen atoms, and optionally Cp* and Ztogether form a fused ring system;

Y is a) a divalent anionic ligand group comprising nitrogen, phosphorus,oxygen or sulfur and having up to 20 non-hydrogen atoms, said Y beingbonded to Z and M through said nitrogen, phosphorus, oxygen or sulfur,and optionally Y and Z together form a fused ring system, or b) acyclopentadienyl group bound in an η⁵ bonding mode to M or such acyclopentadienyl group substituted with from one to four substituentsselected from the group consisting of hydrocarbyl, silyl, germyl, halo,hydrocarbyloxy, amino, and mixtures thereof, said substituent having upto 20 nonhydrogen atoms, or optionally, two substituents together causeY to have a fused ring structure; and

R"' independently each occurrence is a hydrocarbyl group;

the process comprising contacting in the presence of an aprotic organicdiluent a metal coordination complex of formula: ##STR3## wherein Rindependently each occurrence is a hydrocarbyl group having from 1 to 20carbon atoms and Cp*, Z, Y, M, are as previously defined;

with a hydrocarbylation agent comprising a group 1, 2, 12 or 13 metal ormetal derivative and at least one hydrocarbyl group R"', to form themetal dihydrocarbyl coordination complex of formula (II).

In yet another aspect the present invention relates to a process forpreparing a metal dihalide coordination complex corresponding to theformula: ##STR4## wherein: M is titanium, zirconium, or hafnium;

Cp* is a cyclopentadienyl group bound in an η⁵ bonding mode to M or sucha cyclopentadienyl group substituted with from one to four substituentsselected from the group consisting of hydrocarbyl, silyl, germyl, halo,hydrocarbyloxy, amino, and mixtures thereof, said substituent having upto 20 nonhydrogen atoms, or optionally, two substituents together causeCp* to have a fused ring structure;

Z is a divalent moiety comprising boron, or a member of Group 14 of thePeriodic Table of the Elements, and optionally sulfur or oxygen, saidmoiety having up to 50 non-hydrogen atoms, and optionally Cp* and Ztogether form a fused ring system;

Y is a) a divalent anionic ligand group comprising nitrogen, phosphorus,oxygen or sulfur and having up to 20 non-hydrogen atoms, said Y beingbonded to Z and M through said nitrogen, phosphorus, oxygen or sulfur,and optionally Y and Z together form a fused ring system, or b) acyclopentadienyl group bound in an η⁵ bonding mode to M or such acyclopentadienyl group substituted with from one to four substituentsselected from the group consisting of hydrocarbyl, silyl, germyl, halo,hydrocarbyloxy, amino, and mixtures thereof, said substituent having upto 20 nonhydrogen atoms, or optionally, two substituents together causeY to have a fused ring structure; and

X independently each occurrence is a halo group;

the process comprising contacting in the presence of an aprotic organicdiluent a metal coordination complex of formula: ##STR5## wherein Rindependently each occurrence is a hydrocarbyl group having from 1 to 20carbon atoms and Cp*, Z, Y, M, are as previously defined;

with a halogenation agent comprising at least a member of Group 13 or 14of the Periodic Table of the Elements and at least one halo group X, toform the metal dihalide coordination complex of formula (III).

DETAILED DESCRIPTION OF THE INVENTION

All reference to the Periodic Table of the Elements herein shall referto the Periodic Table of the Elements, published and copyrighted by CRCPress, Inc., 1989. Also, any reference to a Group or Groups shall be tothe Group or Groups as reflected in this Periodic Table of the Elementsusing the IUPAC system for numbering Groups.

Surprisingly, it has been found that two hydrocarbyloxy groups on thetitanium center can be removed readily by contacting the compound M(OR)₄with the dianionic salt compound to give the complexes of formulas (I),(Ia), or (Ib) in high yield and high purity. This discovery was indeedsurprising as hydrocarbyloxy-transition metal bonds are considered to bestronger bonds than halogen-transition metal bonds and therefore thehydrocarbyloxy groups are considered less suitable leaving groups thanhalogen groups. The starting metal hydrocarbyloxy compounds, typicallythe titanium tetraisopropoxide, tetra-n-butoxide and tetra-t.-butoxide,are non-viscous liquids, only mildly air-sensitive, commerciallyavailable, and readily soluble in hydrocarbons, as compared to thecorrosive, air-sensitive and difficult to handle titaniumtetrachlorides. This new process provides the complexes of formulas (I),(Ia), and (Ib) in yields of 90 percent and higher. The product complexescan be readily isolated in high purity by filtration.

In the present process bridged mono- or bis(cyclopentadienyl) metaldihydrocarbyloxy coordination complexes of formulas (I), (Ia), or (Ib)are prepared by contacting a titanium tetrahydrocarbyloxy compound ofthe formula: M(OR)₄ with a dianionic salt compound. The dianionic saltis preferably a double Group 1 metal derivative or double Grignard(Group 2 metal monohalide) derivative of the --Cp*--Z--Y-- moiety, theanionic charges formally residing on the Cp* and Y groups. The doubleGroup 1 metal derivative corresponds to (L^(+x))_(y) wherein x is 1 andy is 2, and the double Grignard derivative corresponds to((LX)^(+x))_(y) wherein x is 1 and y is 2.

In the metal dihydrocarbyloxy coordination complexes of formula (I), Mis titanium, and R independently each occurrence is a hydrocarbyl grouphaving from 1 to 20 carbon atoms, more preferably R each occurrence isindependently selected from the group consisting of alkyl, aryl,alkaryl, and aralkyl groups, even more preferably from alkyl groupshaving from 1 to 6 carbon atoms, and aryl, aralkyl and alkaryl groupshaving from 6-10 carbon atoms, and most preferably R each occurrence isindependently selected from the group consisting of isopropyl, n-butyl,and t-butyl.

A neutral Lewis base, such as an ether or amine compound, may also beassociated with the complex, if desired, however, such is generally notpreferred.

The term "substituted cyclopentadienyl" includes indenyl,tetrahydroindenyl, fluorenyl, tetrahydrofluorenyl, andoctahydrofluorenyl groups.

Generic formula (I) embraces bridged monocyclopentadienyl metaldihydrocarbyloxy coordination complexes and bridgedbis(cyclopentadienyl) metal dihydrocarbyloxy coordination complexes.

Preferred bridged monocyclopentadienyl metal dihydrocarbyloxycoordination complexes of formula (I) prepared in the present processinclude those having constrained geometry.

By the term "constrained geometry" as used herein is meant that themetal atom in the metal coordination complex and also in the catalystresulting therefrom is forced to greater exposure of the active catalystsite because of a specific ring structure of a ligand group includingthe metal atom, wherein the metal is both bonded to an adjacent covalentmoiety and held in association with the delocalized π-bondedcyclopentadienyl group through an η⁵ or other π-bonding interaction. Itis understood that each respective bond between the metal atom and theconstituent atoms of the π-bonded moiety need not be equivalent. Thatis, the metal may be symetrically or unsymmetrically π-bound thereto.

The concept of constrained geometry and specific constrain inducingligand groups are described in more detail in U.S. patent applicationSer. No. 545,403, filed Jul. 3, 1990 (corresponding to EP-A-0,416,815)which is incorporated herein by reference.

Suitable examples of moiety Z in formula (I) include SIR*₂, CR*₂, SiR*₂SiR*₂, CR*₂ CR*₂, CR*═CR*, CR*₂ SiR*₂, GeR*2, BR*, or BR*2, wherein R*each occurrence is independently selected from the group consisting ofhydrogen, alkyl, aryl, silyl, halogenated alkyl, halogenated aryl groupshaving up to 20 non-hydrogen atoms, and mixtures thereof, or two or moreR* groups from Z, or an R* group from Z together with Y form a fusedring system.

Further more preferably, Y in formula (I) is --O--, --S--, --NR*--,--PR*--. Highly preferably Y is a nitrogen or phosphorus containinggroup corresponding to the formula --N(R')-- or --P(R')--, i.e. an amidoor phosphido group, wherein R' is as defined hereinafter.

More preferably, in the present process is prepared a metal coordinationdihydrocarbyloxy complex of formula (I) corresponding to the formula:##STR6## wherein R' each occurrence is independently selected from thegroup consisting of hydrogen, silyl, alkyl, aryl, germyl, cyano, haloand combinations thereof having up to 20 non-hydrogen atoms, or two R'groups together form a divalent derivative thereof;

E is silicon or carbon;

m is 1 or 2; and

M and R are as previously defined; and

wherein the metal compound of the formula: M(OR)₄ is contacted with adianionic salt compound corresponding to the formula:

    (L.sup.+x).sub.y (C.sub.5 R'.sub.4 --ER'.sub.2 --NR').sup.-2 or ((LX).sup.+x).sub.y (C.sub.5 R'.sub.4 --ER'.sub.2 --NR').sup.-2

wherein L, R', E, X, x and y are as previously defined.

In the complexes of formula (Ia), M is titanium, and preferably Rindependently each occurrence is alkyl, aryl, aralkyl, and alkarylgroups, more preferably selected from an alkyl group having from 1 to 6carbon atoms, and aryl, aralkyl and alkaryl groups having from 6-10carbon atoms, even more preferably R is isopropyl, n-butyl, or t-butyl.

Examples of the above most highly preferred metal dihydrocarbyloxycoordination compounds include compounds wherein the R' on the amidogroup is methyl, ethyl, propyl, butyl, pentyl, hexyl, and isomers ofthese alkyl radicals, norbornyl, benzyl, phenyl, etc.; thecyclopentadienyl group is cyclopentadienyl, indenyl, tetrahydroindenyl,fluorenyl, tetrahydrofluorenyl, octahydrofluorenyl, etc.; R' on theforegoing cyclopentadienyl groups each occurrence is hydrogen, methyl,ethyl, propyl, butyl, pentyl, hexyl, and isomers of these alkylradicals, norbornyl, benzyl, phenyl, etc.; and R is isopropyl, n-butylor t-butyl.

Specific highly preferred compounds include:(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium di-isopropoxide,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium di-n-butoxide,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium di-isopropoxide,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium di-n-butoxide,(methylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdi-isopropoxide, (methylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium di-n-butoxide,(phenylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdi-isopropoxide, (phenylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium di-n-butoxide,(benzylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdi-isopropoxide, (benzylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium di-n-butoxide,(tert-butylamido)(η⁵ -cyclopentadienyl)-1,2-ethanediyltitaniumdi-isopropoxide, (tert-butylamido)(η⁵-cyclopentadienyl)-1,2-ethanediyltitanium di-n-butoxide,(tert-butylamido)(η⁵ -cyclopentadienyl)dimethylsilanetitaniumdi-isopropoxide, (tert-butylamido)(η⁵-cyclopentadienyl)dimethylsilanetitanium di-n-butoxide, (methylamido)(η⁵-cyclopentadienyl)dimethylsilanetitanium di-isopropoxide,(t-butylamido)(η⁵ -cyclopentadienyl)dimethylsilanetitaniumdi-n-butoxide, (t-butylamido)indenyldimethylsilanetitaniumdi-isopropoxide, (t-butylamido)indenyldimethylsilanetitaniumdi-n-butoxide, (benzylamido)indenyldimethylsilanetitaniumdi-isopropoxide.

According to another preferred embodiment of the present process, thereis prepared a metal coordination complex of formula (I) corresponding tothe formula: ##STR7## wherein: R' each occurrence is independentlyselected from the group consisting of hydrogen, silyl, alkyl, aryl,germyl, cyano, halo and combinations thereof having up to 20non-hydrogen atoms, or two R' groups together form a divalent derivativethereof;

E is silicon or carbon;

R" independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl and combinations thereof, said R" having up to 30carbon or silicon atoms;

m is 1 to 8; and

M and R are as previously defined; and

wherein the metal compound of the formula: M(OR)₄ is contacted with adianionic salt compound corresponding to the formula:

    (L.sup.+x).sub.y (C.sub.5 R'.sub.4 --(ER".sub.2).sub.m --C.sub.5 R'.sub.4).sup.-2

or

    ((LX).sup.+x).sub.y (C.sub.5 R'.sub.4 --(ER".sub.2).sub.m --C.sub.5 R'.sub.4).sup.-2

wherein L, R', E, R", X, m, x and y are as previously defined.

Exemplary metal complexes of bridged bis-cyclopentadienyl metaldihydrocarbyloxy coordination complexes include those complexes offormula (Ib) wherein E is silicon or carbon, R" independently eachoccurrence is hydrogen or a group selected from silyl, hydrocarbyl andcombinations thereof, said R" having up to 30 carbon or silicon atoms,and m is 1 to 8. Preferably R" independently each occurrence is methyl,benzyl, tert-butyl, or phenyl.

Such bridged bis(cyclopentadienyl) structures are especially suited foruse as catalyst, or precursors thereof, for the preparation of polymershaving stereoregular molecular structure. In such capacity it ispreferred that the complex be nonsymmetrical or possess a chiral,stereorigid structure. Examples of the first type are compoundspossessing different delocalized π-bonded systems, such as onecyclopentadienyl group and one indenyl group. Examples of chiralstructures include bis-indenyl complexes.

Exemplary bridged bis(cyclopentadienyl) metal dihydrocarbyloxy complexesof formula (Ib) are those wherein the bridged ligand group is:dimethylsilyl-bis-cyclopentadienyl,dimethylsilyl-bis-tetramethylcyclopentadienyl,dimethylsilyl-bis-indenyl, isopropylidene-cyclopentadienyl-fluorenyl,2,2'-biphenyldiylbis(3,4-dimethyl-1-cyclopentadienyl), and6,6-dimethyl-2,2'-biphenylbis(3,4-dimethyl-1-cyclopentadienyl).

In a preferred embodiment, the moiety ((LX)^(+x))_(y) in the dianionicsalt compound corresponds to ((MgCl)⁺)₂. Use of such a dianionic saltcompound in the present process gives as a byproduct MgCl(OR) which canbe easily separated from the desired product.

The molar ratio of the dianionic salt compound to the metaldihydrocarbyloxy compound M(OR)₄ can vary between wide limits. Althoughan improved process can be obtained with dianionic salt compound tometal compound molar ratios of 0.5:1 and higher, for example, up to10:1, or preferably up to 5:1, the yield of the process and the purityof the desired products are high at ratios of 1:1 and slightly higher,for example, up to 1.5:1, preferably up to 1.2:1.

In the present process an aprotic organic diluent is used. Suitableexamples of such diluents are ethers and hydrocarbons. Preferably thehydrocarbon solvent is an aliphatic or cycloaliphatic hydrocarbonsolvent having from 5 to 10 carbon atoms. Suitable solvents are pentane,hexane, heptane, Isopar E (a mixture of isoparaffinic hydrocarbonsavailable from Exxon Chemical Inc.), isooctane, cyclohexane, andmethylcyclohexane.

Carrying out the reaction in a hydrocarbon solvent has the advantagethat the product dihydrocarbyloxy complexes of formulas (I), (Ia), and(Ib) are soluble, whereas the byproduct L--R or LX--R generally is not.The desired products thus can be easily recovered, if desired, byfiltration or other liquid-solid separation methods. By subjecting theliquid thus obtained to a stripping step to strip off the volatilesolvent a highly pure product is obtained.

The temperature at which the process is conducted is not critical, butis preferably below the boiling point of the diluent. Preferredtemperatures range from 0° C. to 100° C., more preferably from 10° C. to80° C., and most preferably from 20° to 60° C.

Generally the reactants are contacted under an inert atmosphere for atime from several minutes to several days. The presence of oxygen andmoisture are preferably avoided. The reactants can be added in anyorder. Agitation may be employed if desired.

According to a further aspect the present invention provides a processfor preparing bridged mono- or biscyclopentadienyl dihydrocarbyl metalcoordination complexes of formulas (II), (IIa), and (IIb) by contactinga corresponding metal dihydrocarbyloxy coordination complex of formula(I), (Ia), or (Ib) obtainable as described hereinbefore with ahydrocarbylation agent comprising a Group 1, 2, 12 or 13 metal or metalderivative and at least one hydrocarbyl group R"', to form thedihydrocarbyl metal coordination complex of formula (II), (IIa) or(IIb).

Surprisingly, it has been found that the dihydrocarbyloxy complexes offormulas (I), (Ia), and (Ib) are stable compounds which can readily beconverted to the corresponding dihydrocarbyl compounds of formulas (II),(IIa), or (IIb) in high yields and purity. The present hydrocarbylationprocess, especially in combination with the process for preparing themetal dihydrocarbyloxy coordination complexes of formulas (I), (Ia), or(Ib) as described herein before, enables the valuable complexes offormulas (II), (IIa), or (IIb) to be prepared in high overall yieldscompared to a process starting from metal tetrahalide compounds.

In a preferred embodiment, a metal dihydrocarbyl coordination complexcorresponding to the formula: ##STR8##

wherein R' each occurrence is independently selected from the groupconsisting of hydrogen, silyl, alkyl, aryl, germyl, cyano, halo andcombinations thereof having up to 20 non-hydrogen atoms, or two R'groups together form a divalent derivative thereof;

E is silicon or carbon;

m is 1 or 2; and

M and R"' are as previously defined;

is prepared by contacting a metal dihydrocarbyloxy coordination complexcorresponding to the formula: ##STR9## wherein: M, R', E, R, and m areas previously defined; with the hydrocarbylation agent.

In another preferred embodiment, a metal dihydrocarbyl coordinationcomplex corresponding to the formula: ##STR10## wherein: R' eachoccurrence is independently selected from the group consisting ofhydrogen, silyl, alkyl, aryl, germyl, cyano, halo and combinationsthereof having up to 20 non-hydrogen atoms, or two R' groups togetherform a divalent derivative thereof;

E is silicon or carbon;

R" independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl and combinations thereof, said R" having up to 30carbon or silicon atoms;

m is 1 to 8; and

M and R"' are as previously defined;

is prepared by contacting a metal dihydrocarbyloxy coordination complexcorresponding to the formula: ##STR11## wherein R', E, R", M, R, and mare as previously defined; with the hydrocarbylation agent.

In a further preferred embodiment, the metal dihydrocarbyloxycoordination complex of formula (I), (Ia), or (Ib), used as startingcompound in the preparation of complexes of formulas (II), (IIa) or(IIb), is prepared by contacting in the presence of an aprotic organicdiluent a metal compound of the formula: M(OR)₄ wherein M and R are aspreviously defined with a dianionic salt compound corresponding to theformula:

    (L.sup.+x).sub.y (Cp*--Z--Y).sup.-2 or ((LX).sup.+x).sub.y (Cp*--Z--Y).sup.-2

wherein:

L is a metal of Group 1 or 2 of the Periodic Table of the Elements,

X independently is chloro, bromo, or iodo,

x and y are either 1 or 2 and the product of x and y equals 2, and

Cp*, Z, and Y are as previously defined;

optionally followed by recovering the complex corresponding to formula(I).

In the complexes of formulas (I), (Ia), and (Ib), M is titanium, and Rindependently each occurrence is a hydrocarbyl group having from 1 to 20carbon atoms, preferably R each occurrence is independently selectedfrom the group consisting of alkyl, aryl, aralkyl, and alkaryl groups,more preferably alkyl groups having from 2 to 6 carbon atoms and aryl,aralkyl, and alkaryl groups having from 6-10 carbon atoms, and mostpreferably R each occurrence is independently selected from the groupconsisting of isopropyl, n-butyl, and t-butyl.

Preferred embodiments of the present process to prepare the complexes offormulas (I), (Ia), and (Ib) are illustrated hereinbefore and herebyincorporated by reference.

The complexes of formulas (I), (Ia), and (Ib) as obtained can berecovered or purified, if desired, prior to proceeding with thehydrocarbylation step.

The hydrocarbyl group R"' in formulas (II), (IIa), and (IIb) and presentin the hydrocarbylation agent generally has from 1 to 20 carbon atomsand can be an aliphatic, cycloaliphatic, or aromatic hydrocarbon or amixture thereof. Preferably, R"' is selected from the group consistingof alkyl, aryl and aralkyl groups, more preferably from alkyl groupshaving from 1 to 6 carbon atoms, or aralkyl groups having from 7 to 10carbon atoms. Most preferably R"' is methyl, neopentyl, or benzyl.

The hydrocarbylation agent comprises a Group 1, 2, 12 or 13 metal ormetal derivative and at least one hydrocarbyl group R"'. Suitableexamples of the hydrocarbylation agent include LiR"', MgR"'₂, MgR"'X(wherein X is halogen, preferably chloro), AlR"'₃, and R"'-substitutedaluminoxane. Suitable R"'-substituted aluminoxanes preferably includeC₁₋₆ -alkylaluminoxanes, especially methylaluminoxane. Alkylaluminoxanesare well known in the art and methods for their preparation areillustrated by U.S. Pat. Nos. 4,592,199; 4,544,762; 5,015,749 and5,041,585. Preferably, the hydrocarbylation agent comprises LiR"' orAlR"'₃. More preferably the hydrocarbylation agent is trialkyl aluminum,most preferably trimethyl aluminum.

Specific highly preferred complexes of formula (IIa) include:(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dimethyl,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dibenzyl,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dimethyl,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dibenzyl,(methylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdimethyl, (methylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dibenzyl,(phenylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdimethyl, (phenylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dibenzyl,(benzylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdimethyl, (benzylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dibenzyl, (tert-butylamido)(η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dimethyl, (tert-butylamido)(η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dibenzyl, (tert-butylamido)(η⁵-cyclopentadienyl)dimethylsilanetitanium dimethyl, (tert-butylamido)(η⁵-cyclopentadienyl)dimethylsilanetitanium dibenzyl, (methylamido)(η⁵-cyclopentadienyl)dimethylsilanetitanium dimethyl, (t-butylamido)(η⁵-cyclopentadienyl)dimethylsilanetitanium dibenzyl,(t-butylamido)indenyldimethylsilanetitanium dimethyl,(t-butylamido)indenyldimethylsilanetitanium dibenzyl, and(benzylamido)indenyldimethylsilanetitanium dibenzyl.

The molar ratio of the hydrocarbylation agent to the complex of formulas(I), (Ia), and (Ib) can vary between wide limits, but is preferablybetween 0.1:1 and 20:1, more preferably between 0.5:1 to 10:1.Advantageously, an equivalent amount or a slight excess of R"'-groups inthe hydrocarbylation agent is used with respect to the metalhydrocarbyloxy compound of formulas (I), (Ia), or (Ib), i.e., a ratio offrom 2.0:1 to 4.0:1, more preferably of from 2.1:1 to 3:1.

The temperature at which the hydrocarbylation step is conducted is notcritical, but is preferably below the boiling point of the aproticorganic diluent Preferred temperatures range from 0° C. to 100° C., morepreferably from 10° C. to 80° C.

Generally the reactants are contacted under an inert atmosphere for atime from several minutes to several days. The reactants can be added inany order. Agitation may be employed if desired.

In the present hydrocarbylation step an aprotic organic diluent is used.Preferably, diluents are used in which the complexes of formulas (I),(Ia), and (Ib) are readily soluble, optionally upon heating. Suitableexamples of such solvents are ethers and hydrocarbons. Preferably thesolvent is a hydrocarbon, advantageously an aliphatic or cycloaliphatichydrocarbon solvent having from 5 to 10 carbon atoms. Suitable solventsare pentane, hexane, heptane, Isopar E, isooctane, cyclohexane, andmethylcyclohexane.

Carrying out the reaction in a hydrocarbon solvent has the advantagethat the product hydrocarbyl complexes of formulas (II), (IIa), and(IIb) are soluble, whereas the byproduct Group 1, 2, 12 or 13 metal ormetal derivative hydrocarbyloxides are generally not. So are thebyproducts LiOR and Mg(OR)X generally not soluble in hydrocarbons. Thedesired products thus can be easily separated from these insolublebyproducts, if desired, by filtration or other liquid-solid separationmethods. By subjecting the liquid thus obtained to a stripping step tostrip off the volatile solvent a highly pure product is obtained. Whentrimethylaluminum is used as hydrocarbylation agent the byproduct formedcomprises a methylaluminum dihydrocarbyloxyde, which is volatile. Thisbyproduct can be removed from the desired product by applying a vacuumso as to remove both the byproduct and the solvent/diluent in one step.

According to another aspect the present invention provides a process forpreparing bridged mono- or bis(cyclopentadienyl) metal dihalidecoordination complexes of formulas (III), (IIIa) or (IIIb) by contactinga corresponding metal dihydrocarbyloxy coordination complex of formula(I), (ia), or (Ib) obtainable as described hereinbefore, with ahalogenation agent comprising a Group 13 or 14 element or derivativethereof and at least one halo group X, to form the metal dihalidecoordination complex of formulas (III), (IIIa) or (IIIb).

Surprisingly, it has been found that the dihydrocarbyloxy complexes offormulas (I), (Ia) or (b) are stable compounds which can easily beconverted to the corresponding dihalide compounds of formulas (III),(IIIa) or (IIIb) in high yields and purity. The present halogenationprocess, especially in combination with the process for preparing themetal dihydrocarbyloxy coordination complexes of formulas (I), (Ia) or(Ib) as described herein before, enables the complexes of formulas(III), (IIIa) or (IIIb) to be prepared in high yields compared to aprocess starting from metal tetrahalide compounds.

In a preferred embodiment, a metal dihalide coordination complexcorresponding to the formula (IIIa): ##STR12## wherein R' eachoccurrence is independently selected from the group consisting ofhydrogen, silyl, alkyl, aryl, germyl, cyano, halo and combinationsthereof having up to 20 non-hydrogen atoms, or two R' groups togetherform a divalent derivative thereof;

E is silicon or carbon;

m is 1 or 2; and

M and X are as previously defined;

is prepared by contacting a metal dihydrocarbyloxy coordination complexcorresponding to the formula: ##STR13## wherein: M, R', E, R, and m areas previously defined; with the halogenation agent.

In another preferred embodiment, a metal dihalide coordination complexcorresponding to formula (IIIb) ##STR14## wherein: R' each occurrence isindependently selected from the group consisting of hydrogen, silyl,alkyl, aryl, germyl, cyano, halo and combinations thereof having up to20 non-hydrogen atoms, or two R' groups together form a divalentderivative thereof;

E is silicon or carbon;

R" independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl and combinations thereof, said R" having up to 30carbon or silicon atoms;

m is 1 to 8; and

M and X are as previously defined;

is prepared by contacting a metal dihydrocarbyloxy coordination complexcorresponding to the formula: ##STR15## wherein R', E, R", M, R, and mare as previously defined; with the halogenation agent.

In a further preferred embodiment, the metal dihydrocarbyloxycoordination complex of formulas (I), (Ia) or (Ib), used as startingcompound in the preparation of complexes of formulas (III), (IIIa) or(IIIb), is prepared by contacting in the presence of an aprotic organicdiluent a metal compound of the formula: M(OR)₄ wherein M and R are aspreviously defined with a dianionic salt compound corresponding to theformula:

    (L.sup.+x).sub.y (Cp*--Z--Y).sup.-2 or ((LX).sup.+x).sub.y (Cp*--Z--Y).sup.-2

wherein:

L is a metal of Group 1 or 2 of the Periodic Table of the Elements,

X independently is chloro, bromo, or iodo,

x and y are either 1 or 2 and the product of x and y equals 2, and

Cp*, Z, and Y are as previously defined;

optionally followed by recovering the complex corresponding to formula(I).

In the complexes of formulas (I), (Ia), and (Ib), M is titanium, and Rindependently each occurrence is a hydrocarbyl group having from 1 to 20carbon atoms, preferably R each occurrence is independently selectedfrom the group consisting of alkyl, aryl, aralkyl, and alkaryl groups,more preferably alkyl groups having from 2 to 6 carbon atoms and aryl,aralkyl, and alkaryl groups having from 6-10 carbon atoms, and mostpreferably R each occurrence is independently selected from the groupconsisting of isopropyl, n-butyl, and t-butyl.

Preferred embodiments of the present process to prepare the complexes offormulas (I), (Ia), and (Ib) are illustrated hereinbefore and herebyincorporated by reference.

The complexes of formulas (I), (Ia), and (Ib) as obtained can berecovered or purified, if desired, before proceeding with thehalogenation process.

The halo group X in formulas (III), (IIIa), and (IIIb) and in thehalogenation agent can be chloro, bromo, or iodo, but is preferablychloro.

The halogenation agent comprises a Group 13 or 14 element or derivativethereof and at least one halo group X. Suitable examples of thehalogenation agent include the halides, preferably chlorides, of boron,aluminum and silicon. Preferably, the halogenation agent is selectedfrom the group consisting of silicon tetrachloride, boron trichloride,and alkylaluminum chlorides, more preferably dialkylaluminum chloridessuch as diethylaluminum chloride. Most preferred halogenation agents aresilicon tetrachloride and boron trichloride.

Specific highly preferred complexes of formula IIIb include:(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dichloride,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dichloride,(methylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdichloride, (phenylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium dichloride,(benzylamido)(tetramethyl-η⁵ -cyclopentadienyl)dimethylsilanetitaniumdichloride, (tert-butylamido)(η⁵-cyclopentadienyl)-1,2-ethanediyltitanium dichloride,(tert-butylamido)(η⁵ -cyclopentadienyl)dimethylsilanetitaniumdichloride, (methylamido)(η⁵ -cyclopentadienyl)dimethylsilanetitaniumdichloride, and (t-butylamido)indenyldimethylsilanetitanium dichloride.

The molar ratio of the halogenation agent to the complex of formulas(I), (Ia), and (Ib) can vary between wide limits, but is preferablybetween 0.1:1 and 20:1, more preferably between 0.5:1 to 10:1.Advantageously, an equivalent amount or slight stoichiometric excess ofhalogenation agent is used with respect to the metal dihydrocarbyloxycompound of formula (I), (Ia) or (Ib), i.e. a ratio of 2.0:1 to 4.0:1,more preferably of from 2.1:1 to 3:1.

The temperature at which the halogenation step is conducted is notcritical, but is preferably below the boiling point of the diluent.Preferred temperatures range from 0° C. to 100° C., more preferably from10° C. to 80° C.

Generally the reactants are contacted under an inert atmosphere for atime from several minutes to several days. The reactants can be added inany order. Agitation may be employed if desired.

In the present halogenation step an aprotic organic diluent is used.Preferably, diluents are used in which the complexes of formulas (I),(Ia), and (Ib) are readily soluble, optionally upon heating. Suitableexamples of such solvents are ethers and hydrocarbons. Preferably thesolvent is a hydrocarbon, advantageously an aliphatic or cycloaliphatichydrocarbon solvent having from 5 to 10 carbon atoms. Suitable solventsare pentane, hexane, heptane, Isopar E, isooctane, cyclohexane, andmethylcyclohexane.

In general, isolation of the desired complexes can take place asrequired by the byproducts. Removal of volatiles, such as the solvent,is preferably carried out by vacuum distillation at elevatedtemperatures. For example, when silicon tetrachloride is used ashalogenation agent the byproduct formed comprises a hydrocarbyloxysilicon chloride, which is volatile. This byproduct can be easilyremoved from the desired product by using vacuum distillation. Highlypure products are generally obtained, as compared to the prior artmethods which require extensive filtration and recrystallization steps.

The compounds prepared with the processes according to the presentinvention, that is the complexes of formulas (I), (Ia), (Ib), (II),(IIa), (IIb), (III), (IIIa) and (IIIb) can be used as components ofcatalyst systems, or precursors therefor, useful in additionpolymerization processes.

In a process for preparing a polymer of one or more additionpolymerizable monomers, a catalyst comprising a metal coordinationcomplex of any of the above-mentioned formulas and an activatingcocatalyst are contacted with one or more addition polymerizablemonomers under addition polymerization conditions. Suitable activatingcocatalysts are described in U.S. patent application Ser. No. 545,403,filed Jul. 3, 1990 (corresponding to EP-A-0,416,815) and Ser. No.817,202, filed Jan. 6, 1992 (corresponding to WO-A-92/10360), which areincorporated herein by reference.

"Addition polymerizable monomers" include for example ethylenicallyunsaturated monomers, conjugated or nonconjugated dienes, polyenes, etc.Preferred monomers include the C₂₋₁₀ α-olefins especially ethylene,propylene, isobutylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and1-octene. Other preferred monomers include styrene, halo- or alkylsubstituted styrene, vinylbenzocyclobutane, 1,4-hexadiene,ethylidenenorbornene, cyclopentene, and norbornene.

Suitable catalysts for use according to the present invention areprepared by combining the metal coordination complex of formulas (I),(II), or (III) and activating cocatalyst compound in any order and inany suitable manner. Preferably the ratio of the coordination complexand cocatalyst on a molar basis is from about 1:0.1 to about 1:10,000.It will, of course, be appreciated that the catalyst system may also beformed in situ if the components thereof are added directly to thepolymerization process and a suitable solvent or diluent, includingcondensed monomer, is used in said polymerization process. Suitablesolvents include toluene, ethylbenzene, alkanes and mixtures thereof. Incertain cases the catalysts may be isolated from solution and retainedunder inert atmosphere prior to use. The catalysts' components aresensitive to both moisture and oxygen and should be handled andtransferred in an inert atmosphere such as nitrogen, argon or helium orunder vacuum.

The polymerization is conducted according to known techniques forZiegler-Natta or Kaminsky-Sinn type polymerizations. That vs, themonomer(s) and catalyst are contacted at a temperature from -30° C. to250° C., at reduced, elevated or atmospheric pressures. Thepolymerization is conducted under an inert atmosphere which may be ablanketing gas such as nitrogen, argon, hydrogen, ethylene, etc. orunder vacuum. Hydrogen may additionally be utilized in the control ofmolecular weight through chain termination as is previously known in theart. The catalyst may be used as is or supported on a suitable supportsuch as alumina, MgCl₂ or silica to provide a heterogeneous supportedcatalyst. A solvent may be employed if desired. Suitable solventsinclude toluene, ethylbenzene, alkanes and excess vinyl aromatic orolefin monomer. The reaction may also be conducted under solution orslurry conditions, in a suspension utilizing a perfluorinatedhydrocarbon or similar liquid, in the gas phase, i.e. utilizing afluidized bed reactor, or in a solid phase powder polymerization. Acatalytically effective amount of the present catalyst and cocatalystare any amounts that successfully result in formation of polymer. Suchamounts may be readily determined by the routine experimentation by theskilled artisan. Preferred amounts of catalyst and cocatalyst aresufficient to provide an equivalent ratio of addition polymerizablemonomer:catalyst of from 1×10¹⁰ :1 to 100:1, preferably from 1×10⁸ :1 to500:1, most preferably 1×10⁶ :1 to 1000:1. The cocatalyst is generallyutilized in an amount to provide an equivalent ratio ofcocatalyst:catalyst from 10,000:1 to 0.1:1, preferably from 1,000:1 to1:1.

It is to be understood that the metal complex may undergo varioustransformations or form intermediate species prior to and during thecourse of a polymerization. Thus other precursors could possibly beconceived to achieve the same catalytic species as are herein envisionedwithout departing from the scope of the present invention.

The resulting polymeric product is recovered by filtering or othersuitable technique. Additives and adjuvants may be incorporated in thepolymers of the present invention in order to provide desirablecharacteristics. Suitable additives include pigments, UV stabilizers,antioxidants, blowing agents, lubricants, plasticizers,photosensitizers, and mixtures thereof.

Having described the invention, the following examples are provided tofurther illustrate the same and are not to be construed as limiting.

EXAMPLE 1 Preparation of (Tert-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silane titanium diisopropoxide

In a drybox, 24.95 g of titaniumtetraisopropoxide (Ti(O^(i) Pr)₄)(Aldrich Chemical Company) (88 mmol) is dissolved in about 200 ml ofhexane. 58 g of soliddi(chloromagnesium)(tert-butylamido)-dimethyl(tetramethylcyclopentadienyl)silanecomplexed with dimethoxyethane, Me₄ C₅ SiMe₂ N^(t) Bu! MgCl!₂ (DME)_(n)(effective molecular weight by titration: about 629 g/mole; 92 mmol)(prepared according to the following procedure: In an apparatusconsisting of a 3 l round bottom flask which was equipped with astirrer, a condenser, and a nitrogen inlet was loaded 500 ml of toluene,followed by 106 g of Me₄ C₅ HSiMe₂ NH^(t) Bu, and then 380 ml of 2.2M^(i) PrMgCl in Et₂ O. The mixture was then heated, and the ether removedby distillation and trapped in a condenser cooled to -78° C. After fivehours of heating, the heater was turned off, and 450 ml ofdimethoxyethane (DME) was slowly added to the hot, stirred solution,resulting in the precipitation of a white solid. The solution wasallowed to cool to room temperature, the solid was allowed to settle,and the supernatant was decanted from the solid. The solid wasresuspended in Isopar E and filtered. 210 g (79 percent yield) Me₄ C₅SiMe₂ N^(t) Bu! MgCl!₂ (DME)_(n) was obtained as off-white solid.) isadded to the flask, using about 50 ml of additional hexane. The mixtureis stirred overnight at room temperature, then filtered through a mediumporosity fritted glass filter (10-15 μm porosity). The solids remainingon the frit are washed with additional hexane until the washings arecolorless. A yellow/orange solution is obtained, and the volatilematerials are removed from this solution under reduced pressure to leave(Me₄ C₅ SiMe₂ N^(t) Bu)Ti(O^(i) Pr)₂ as a yellow crystalline solid inessentially quantitative yield. ¹ H NMR (C₆ D₆): 4.57 ppm (septet, 2H),2.16 ppm (s, 6H), 1.91 ppm (s, 6H), 1.37 ppm (s, 9H), 1.15 ppm (d, 12H),and 0.65 ppm (6H).

EXAMPLE 2 Preparation of (Tert-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silane titanium dichloride

In a drybox, 5.0 g of (Me₄ C₅ SiMe₂ N^(t) Bu)Ti(O^(i) Pr)₂ (12.0 mmol)is dissolved in about 50 ml of hexane. Silicon tetrachloride (Aldrich,99.999%, 2.9 ml, 25.3 mMol) is added by syringe. The color immediatelydarkens and a precipitate begins to form. The reaction mixture isstirred overnight (about 18 hours). At the end of this time, thevolatile materials are removed under reduced pressure to leave (Me₄ C₅SiMeN^(t) Bu)TiCl₂ as a yellow solid (4.35 g, 98% yield). The materialis identified by comparison of its ¹ H NMR spectrum with spectra of thecomplex made by other routes. ¹ H NMR (C₆ D₆): 2.00 ppm (s, 6H), 1.99ppm (s, 6H), 1.42 ppm (s, 9H), 0.42 ppm (s, 6H).

EXAMPLE 3 Preparation of (Tert-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silane titanium dimethyl

In a drybox, 0.26 g of (Me₄ C₅ SiMe₂ N^(t) Bu)Ti(O^(i) Pr)₂ (0.63 mMol)is dissolved in about 15 mL of hexane. Trimethylaluminum (Aldrich, 2M inhexane, 0.95 ml, 1.9 mmol) is added by syringe. The solution is heatedto gentle reflux. After overnight (about 18 hours) reflux, the solutionturned brown. The volatile materials are then removed under reducedpressure to leave (Me₄ C₅ SiMe₂ N^(t) Bu)TiMe₂ as a pale brown solid.The material is identified by comparison of its ¹ H NMR spectrum withspectra of the complex made by other routes. ¹ H NMR (C₆ D₆): 1.96 ppm(s, 6H)), 1.85 ppm (s, 6H), 1.56 ppm (s, 9H), 0.51 ppm (s, 6H), 0.43 ppm(s, 6H).

What is claimed is:
 1. A process for preparing a metal dihydrocarbylcoordination complex corresponding to the formula: ##STR16## wherein: Mis titanium;Cp* is a cyclopentadienyl group bound in an η⁵ bonding modeto M or such a cyclopentadienyl group substituted with from one to foursubstituents selected from the group consisting of hydrocarbyl, silyl,germyl, halo, hydrocarbyloxy, amino, and mixtures thereof, saidsubstituent having up to 20 nonhydrogen atoms, or optionally, twosubstituents together cause Cp* to have a fused ring structure; Z is adivalent moiety comprising boron, or a member of Group 14 of thePeriodic Table of the Elements, and optionally sulfur or oxygen, saidmoiety having up to 50 non-hydrogen atoms, and optionally Cp* and Ztogether form a fused ring system; Y is a) a divalent anionic ligandgroup comprising nitrogen, phosphorus, oxygen or sulfur and having up to20 non-hydrogen atoms, said Y being bonded to Z and M through saidnitrogen, phosphorus, oxygen or sulfur, and optionally Y and Z togetherform a fused ring system, or b) a cyclopentadienyl group bound in an η⁵bonding mode to M or such a cyclopentadienyl group substituted with fromone to four substituents selected from the group consisting ofhydrocarbyl, silyl, germyl, halo, hydrocarbyloxy, amino, and mixturesthereof, said substituent having up to 20 nonhydrogen atoms, oroptionally, two substituents together cause Y to have a fused ringstructure; and R"' independently each occurrence is a hydrocarbyl group;the process comprising contacting in the presence of an aprotic organicdiluent a metal coordination complex of formula: ##STR17## wherein Rindependently each occurrence is a hydrocarbyl group having from 1 to 20carbon atoms and Cp*, Z, Y, M, are as defined for formula (II); with ahydrocarbylation agent comprising a group 1, 2, 12 or 13 metal or metalderivative and at least one hydrocarbyl group R"', to form the metaldihydrocarbyl coordination complex of formula (II).
 2. A processaccording to claim 1 wherein a metal dihydrocarbyl coordination complexcorresponding to the formula: ##STR18## wherein: R' each occurrence isindependently selected from the group consisting of hydrogen, silyl,alkyl, aryl, germyl, cyano, halo and combinations thereof having up to20 non-hydrogen atoms, or two R' groups together form a divalentderivative thereof;E is silicon or carbon; m is 1 or 2; M is titanium;and R"' is as defined for Formula II in claim 1;is prepared bycontacting a metal dihydrocarbyloxy coordination complex correspondingto the formula: ##STR19## wherein: M, R', E, and m are as previouslydefined for Formula (IIa), and R is as defined for Formula (I) in claim1;with the hydrocarbylation agent.
 3. A process according to claim 1wherein a metal dihydrocarbyl coordination complex corresponding to theformula: ##STR20## wherein: R' each occurrence is independently selectedfrom the group consisting of hydrogen, silyl, alkyl, aryl, germyl,cyano, halo and combinations thereof having up to 20 non-hydrogen atomsor two R' groups together form a divalent derivative thereof;E issilicon or carbon; R" independently each occurrence is hydrogen or agroup selected from silyl, hydrocarbyl and combinations thereof, said R"having up to 30 carbon or silicon atoms; m is 1 to 8; M is titanium; andR"' is as defined for Formula II in claim 1;is prepared by contacting ametal dihydrocarbyloxy coordination complex corresponding to theformula: ##STR21## wherein R', E, R", M, and m are as defined forFormula (IIb), and R is as defined for Formula (I) in claim 1;with thehydrocarbylation agent.
 4. A process according to claim 1 wherein themetal coordination complex corresponding to formula (I) is prepared bycontacting in the presence of an aprotic organic diluent a metalcompound of the formula: M(OR)₄ wherein M is titanium and R is asdefined for formula (I) in claim 1 with a dianionic salt compoundcorresponding to the formula:

    (L.sup.+x).sub.y (Cp*--Z--Y).sup.-2 or ((LX).sup.+x).sub.y (Cp*--Z--Y).sup.-2

wherein: L is a metal of Group 1 or 2 of the Periodic Table of theElements, X independently is chloro, bromo, or iodo, x and y are either1 or 2 and the product of x and y equals 2, and Cp*, Z, and Y are asdefined for formula (II) in claim 1; optionally followed by recoveringthe complex corresponding to formula (I).
 5. A process according toclaim 1 wherein R each occurrence is independently selected from thegroup consisting of alkyl, aryl, aralkyl, and alkaryl groups.
 6. Aprocess according to claim 5 wherein R each occurrence is independentlyselected from the group consisting of alkyl groups having from 2 to 6carbon atoms and aryl, aralkyl, and alkaryl groups having from 6-10carbon atoms.
 7. A process according to claim 6 wherein R eachoccurrence is independently selected from the group consisting ofisopropyl, n-butyl, and t-butyl.
 8. A process according to claim 1wherein R"' is selected from the group consisting of alkyl, aryl, andaralkyl groups.
 9. A process according to claim 8 wherein R"' is amethyl, benzyl, or neopentyl group.
 10. A process according to claim 1wherein the hydrocarbylation agent is selected from the group consistingof R"'Li, R"'₂ Mg, R"'MgCl, R"'₃ Al, and R"'-substituted aluminoxanes.11. A process according to claim 1 wherein the hydrocarbylation agent isR"'Li or R"'₃ Al.
 12. A process according to claim 11 wherein thehydrocarbylation agent is trimethylaluminum.
 13. A process according toclaim 1 wherein the aprotic organic diluent is a hydrocarbon or anether.
 14. A process according to claim 13 wherein the hydrocarboncomprises an aliphatic or cycloaliphatic hydrocarbon solvent having from5 to 10 carbon atoms.
 15. A process according to claim 1 wherein theprocess is conducted at a temperature between 0° and 100° C.